#include <iostream>
#include <algorithm>
#include <string>
#include <queue>
#include <vector>
#include <map>
#include <cstdio>
#include <cmath>
#define INF 100000000
using namespace std;

int main() {
	string s;
	cin >> s;
	int mini = INF;
	for (int i = 0; i < s.size(); i++) {
		int cnt = 0, cflag = 0, wflag = 0;
		for (int j = i; j < s.size(); j++) {
			if (s[j] == 'c')cflag = 1;
			if (cflag == 1)cnt++;
			if (cflag == 1 && wflag == 1 && s[j] == 'w') {
				if (cnt != 0) mini = min(cnt, mini);
				break;
			}
			if (s[j] == 'w'&&cflag == 1)wflag = 1;
			
		}
		//cout << cnt << endl;
	}
	if (mini == INF)mini = -1;
	cout << mini << endl;
	return 0;
}